The present invention relates to an LSI automated design system capable of effectively utilizing design property.
To achieve an LSI automated design system, a variety of CAD tools have been recently developed. However, when designing a circuit with the use of a plurality of CAD tools, it is required to prepare a dedicated converter for forwarding a design work since such CAD tools lack data conformity. Further, in order to use CAD tools in the respective optimum manners, it is required to know thoroughly a method of invoking each of the tools and interfaces among the tools. Thus, it disadvantageously takes much time to use CAD tools.
As means for solving such a problem, there has been developed an integration system for LSI designing CAD tools which is called a framework. This framework has, in addition to a function of integrating CAD tools, a variety of functions including a function of managing design procedures (design processes) to navigate the execution of design tools according to a design methodology, a function of managing design data to be entered in and supplied from the design tools, a design data edition number managing function of managing the version and revision of design data groups.
An example of the framework above-mentioned is shown in "A Process Scheduling Technique and an Interface Builder for CAD Tool Integration" by Toshiaki MIYAZAKI et al, Automated Design/Research Report No. 56-1, 1991, pp 1 to 8. In this example, the design procedures are managed by using a graphic interface called a design flow-chart editor. That is, the design procedures can be managed based on the relation between CAD tools set by the design flow-chart editor and input/output data thereof. Further, data designed by a designer can be readily utilized by another designer.
To efficiently design a high-performance LSI, it is important to flexibly reuse existing design data to improve the design efficiency. As above-mentioned, the framework achieves an LSI automated design by managing design data and design procedures. However, an actual LSI is formed by combination of a variety of circuits and there is the optimum design procedure for each of the circuits. Accordingly, it is difficult to obtain a circuit satisfying a desired performance, merely by forwarding a design work with the application of design procedures previously prepared in the framework. In such an automated design with the reuse of existing design data using the framework, it is difficult to automatically generate a circuit satisfying a required performance since these existing design data to be reused are not related to information relating to the optimum design procedures for the design data.
As a conventional art relating to LSI automated design, there is known a method in which logic circuit modules, each having a function, are previously stored, as wiring information among logic gates, in a develop data storage of a computer such that, when required during logic design, suitable logic circuit modules are retrieved from the develop data storage, thereby to generate a logic circuit of the logic gate level. Such a conventional art can be used for generating functional modules having low-level functions such as a register, a counter, an incrementer or the like, but cannot be used for generating general functional modules having sophisticated functions. Further, it is required to enter a combination of functional modules in the form of a functional diagram with attention placed on the wiring of module terminals. Such a conventional art lacks flexibility in that a reuse design with the use of already designed circuit data, can be effected only on functional modules such as so-called soft-macro or hard-macro of which logics or layouts are fixed.
Prior art as an example of a method of solving the problem above-mentioned, is disclosed in U.S. Pat. No. 4,964,056. Such a prior art is arranged such that functional modules having sophisticated functions such as a control module for controlling the execution of a micro-program, are flexibly reused for designing. More specifically, elements forming functional modules and information about the operations of the modules are previously stored in a computer such that there is automatically synthesized a logic circuit of functional modules including an irregular logic circuit so arranged as to satisfy the demand for the functional modules from the user or logic designer.
Even with such a prior art, the scope of circuit elements to be used for reuse design cannot be extended to all control modules, but can be extended only to portions thereof. In this connection, such a prior art is not effective in designing LSIs having sophisticated functions such as CPU, FPU and the like in a micro-processor or a micro-controller. More specifically, such a prior art cannot be applied to a circuit in which circuit elements lack versatility in operational models, causing the inside states of the functional modules to be complicated.